Expected value is a term from statistics that seems so self-explanatory and ubiquitous in advantage gambling that I'm not sure it should qualify as jargon.

Regardless the general problem of jargon is not as simple as you represent it to be. Jargon can be used to give the appearance of expertise where there is none (for example in paranormal investigations) or it can be used to communicate precise concepts within a specific body of knowledge shared by those communicating. For example, doctors discussing a possible diagnosis.